CR14_10 STMICROELECTRONICS [STMicroelectronics], CR14_10 Datasheet - Page 22

• Manufacturer Part Number: CR14_10
• Description: ISO14443 type-B contactless coupler chip with anti-collision and CRC management
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Applying the I²C protocol to the CR14 registers
5
5.1
Figure 10. Host-to-CR14 transfer: I²C write to parameter register
Figure 11. CR14-to-host transfer: I²C random address read from parameter register
Figure 12. CR14-to-host transfer: I²C current address read from parameter register
22/47
CR14 Read
Bus Master
Bus Slave
S
T
A
R
T
CR14 Write
Applying the I²C protocol to the CR14 registers
I²C parameter register protocol
Figure 10
becomes active after the I²C STOP condition.
Figure 11
sends the Parameter Register contents until it receives a NoACK from the I²C Host.
The CR14 supports the I²C Current Address and Random Address Read modes. The
Current Address Read mode can be used if the previous command was issued to the
register where the Read is to take place.
Bus Master
Bus Slave
1 0 1 0 X X X
Device Select
CR14 Read
Bus Master
Bus Slave
Code
shows how new data is written to the Parameter Register. The new value
shows how to read the Parameter Register contents. The CR14 sends and re-
S
T
A
R
T
1 0 1 0 X X X
Device Select
R/W
S
T
A
R
T
ACK
Code
1 0 1 0 X X X
Parameter Register
Device Select
Code
Address
R/W
00h
Doc ID 11922 Rev 2
ACK
Parameter Register
R/W
ACK
Address
ACK
00h
R
E
S
T
A
R
T
Register Byte
1 0 1 0 X X X
data
Value
Device Select
ACK
Code
NoACK
Register Byte
Value
data
R/W
S
T
O
P
ACK
Register Byte
ACK
ai12040
data
Value
S
T
O
P
ai12038
NoACK
ai12039
CR14
S
T
O
P